Burglar-proof key.



H. O. JOHNSON.

BURGLAR PROOF KEY. APPLIGATION FILED APR. 2, 191s.v

1,084,942, Patented! Jan. 20, 1914.

may:

5 llllllflll' lllllllllllih WWW .Hwns 0. Johnson COLUMBIA PLANDGRAI'H c c,

I] TED STATES FATENT OFFICE.

HANS O. JOHNSON, OF SACRAMENTO, CALIFORNIA, ASSIGNOB, OF ONE-HALF '10 JAMES H. NICHOLSON, OF SACRAMENTO, CALIFORNIA.

BURGLAR-PROOF KEY.

To all whom it may concern:

Be it known that I, HANS O. JOHNSON, a citizen of the United States, residing at Sacramento, in the county of Sacramento, State of California, have invented certain new and useful Improvements in Burglar- Proof Keys; and I do declare the following to be a clear, full, and exact description of the same, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to improvements in safety devices for preventing the picking of locks by burglars, the object of the invention being to produce a key which can be inserted in the lock and when inserted be so fastened in position in the lock as to prevent the key from being removed without removing the entire locr or breaking the door which would render it practically impossible for any person with a skeleton key, jimmy or other device to penetrate and pick the lock to gain an entrance to the dwelling as is now so commonly done.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly ef fective for the purposes for which it is designed.

These objects, I accomplish by means of such structure and relative arrangement of the parts as will fully appear by a perusal of the following specification and claims.

On the drawings, similar characters of reference indicate corresponding parts in the several views.

Figurelis a sectional view of a lock showing my improved key in position. Fig. 2 is a side view of the key partly in section. Fig. 3 is a fragmentary view of the expanding fingers of the key. Fig. 4 is an end view of the subject matter shown in Fig. 3 showing, by dotted lines, the position of the fingers when expanded.

Referring now more particularly to the characters of reference on the drawings, the numeral 1 designates the door, the numeral 2 the lock thereon, and the numeral 3 designates the key hole.

My improved device consists of the key proper, at which is provided with a tapered shoulder 5 projecting from which is a Specification of Letters Patent.

Application filed April 2, 1913.

Patented Jan. 24), 1914:.

Serial No. 758,291.

straight threaded pin 6 slidable over which is a sleeve 7 having a plurality of expansible fingers 8 provided with annular recesses 9. Screw mounted on the threaded pin 6 is a knurled nut 10.

In practice, the key is inserted into the lock until the recesses 9 are in alinement with the edges of the side of the lock around the key hole and then the nut 10 is advanced upon the pin 6 and engages the sleeve 7 forcing the finger members 8 to ride up the tapered portion 5 which expands the said finger members 9 to receive the edges of the side of the look around the key hole into the recesses 9 and hence the sides of said recesses fit on each side of the edge of the lock around the key hole and prevent the removing of the key without the removal of the lock or the breaking of the door.

The numeral 11 designates a ringby means of which my improved device may be attached to a key ring.

To remove the device from the lock, the above described operation is reversed which permits the expansible fingers 8 to contract into normal position releasing them from engagement with the side of the lock.

From the foregoing description it will readily be seen that I have produced such a device as substantially fulfils the objects of the invention as set forth herein.

WVhile this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. A device of the character described comprising a member having a tapered shoulder, a projecting pin on said shoulder, a slidable sleeve on said pin, a plurality of expansible finger members on said sleeve adapted to be mounted on said shoulder,said finger members being provided with annular grooves and means for moving said sleeve on said pin and holding it in fixed position, as described. I

2. A device of the character described comprising a member, a projecting pin on said member, expansible finger members slidably mounted on said pin, means for expanding said finger members, and means 10 nut mounted on said threaded pin and adapted to engage said sleeve to mount said finger members on said tapered shoulder, as described.

In testimony whereof I afiix my signature in presence of two Witnesses.

HANS O. JOHNSON.

WVitnesses:

STEPHEN M. BLEVVETT, VERADINE WARNER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

